The invention generally relates chemical dispensing systems, and in particular, to systems, methods, and software products for analyzing solutions dispensed by a chemical dispensing system.
The dispensing of liquid chemical products from one or more chemical receptacles is a common requirement of many industries, such as the ware-wash, laundry, animal health, and food and beverage industries. For example, in an industrial laundry facility, each of several washing machines must be provided with aqueous solutions containing various quantities of alkaloid, detergent, bleach, starch, softener, and/or other chemical products. Dispensing improper amounts of these chemical products may reduce the effectiveness of the washing process. Moreover, in certain operating environments, the amount of chemicals dispensed by the dispenser must be verified to ensure compliance with regulations. For example, health departments may require that solutions used for sanitation in the healthcare and food preparation industries contain a minimum level of a chemical disinfectant.
To ensure proper amounts of chemical products are being delivered to the machines by a chemical dispensing system, monitoring systems have been developed that monitor the flow of product to the machines. These systems typically rely on electrical sensors that require conductive probes which are in contact with the chemical solutions. The conductive probes are thus subject to corrosion and the buildup of deposits that can affect measurement accuracy. Electrical conductivity measurements also tend to be unreliable due to different products having similar electrochemical characteristics and due to unpredictable interactions between chemical products and different impurities in the water provided by different municipal sources. In some cases, adding a small amount of chemical product to a diluent simply fails to change the electrical conductivity of the resulting solution sufficiently to provide an accurate measurement.
Unreliable monitoring systems may result in the machines attached to the chemical dispensing system running without the required amounts of the chemical products. Thus, the performance of the machines may be adversely affected due to too little or too much of the product being dispensed. This may reduce the quality of a machine's output and/or increase expenses by wasting chemical product or requiring items to be re-processed.
Conventional chemical dispensing systems also do not provide a positive confirmation that the system provided the precise amount of chemical called for by the dispensing program. Moreover, it is often difficult to directly measure the precise concentration of chemical product in the solution being dispensed. Thus, dispensing systems are often unable to consistently maintain the required concentrations of chemical solutions for many applications. Systems that monitor the amount of chemical product dispensed, such as by logging pump run, solenoid activation, or dispense times at the system controller, typically do not satisfy compliance monitoring requirements. This is due to the possibility that merely monitoring operation of the dispenser does not ensure the type and percentage of chemicals in the solution being dispensed by the dispensing system. For example, changes in water pressure, chemical product or water leaks, out of product conditions, or other variations in the dispensing system may cause the concentration of chemicals in the solution to be different than would be expected based solely the amount of chemical dispensed.
Therefore, there is a need for improved apparatuses, methods, and software products for monitoring the delivery of chemical products in chemical dispensing systems.